Known are flow measuring devices with measuring tubes, which have an outer tube of metal support material, which is equipped with a first ply of a corrosion resistant and diffusion blocking, synthetic material, the so-called liner. This material protects the outer tube from aggressive media.
Problematic in the case of usual liner materials installed in flow measuring devices is that they have poor volume stability and are not abrasion resistant. As a result of deformation and abrasion, thus in the case of mechanical loading of the liner material by the measured medium, measurement errors occur in the ascertaining of the flow.
It is, thus, an object of the present invention to provide a more exact flow measurement.